No abstract

Until now, the major problem of methane conversion is to break the very strong C-H bond. It is possible by employing some catalytic methods. However, the formation of carbon powder diminishes the catalytic performance. The use of a gliding arc, described in this work, has two objectives: the hydrogen production and other syngas such as acetylene, and the treatment of the green house gas methane. A good approximation model describing the chemical processes concerning the methane decomposition is described, first by the interaction of key radicals such as CH3 and H, followed by chemical reactions involving other hydrocarbons. Furthermore, the experimental results demonstrated the ability of the gliding arc to accelerate chemical reactions at low temperatures while decreasing energetic cost.

The membranes’ role is of supreme importance in the separation of compounds under different phases of matter. The topic addressed here is based on the use of membranes on the gases separation, specifically the advantages of mixed-matrix membranes (MMMs) when using carbon nanotubes as fillers to separate carbon dioxide (CO2) from other carrier gas. MMMs consist of a polymer support with additive fillers to improve their efficiency by increasing both selectivity and permeability. The most promising fillers in the MMM development are nanostructured molecules. Due to the good prospects of carbon nanotubes (CNTs) as MMM fillers, this article aims to concentrate the advances and developments of CNT–MMM to separate gases, such as CO2. The influence of functionalized CNT or mixtures of CNT with additional materials such as zeolites, hydrogel and, graphene sheets on membranes performance is highlighted in the present work.

Some recent results concerning the synthesis of carbon nanostructures in a thermal plasma generating by a plasma torch are presented. Several tests were carried out in different operational conditions. The plasma was formed with argon and different gas mixtures of argon-acetylene or argon-methane to which some catalyst materials (ferrocene and cerium oxide) were added. These catalysts were introduced into the plasma in a solid (powder) or/and a gaseous state. Their feeding rate into the plasma jet was fixed along with some other operating conditions such as plasma power, gas flow rate and reactor pressure. The principal main feature observed was a short reaction time so that each test lasted for no longer than 5 minutes. The solid products obtained were collected and prepared for following analyses. The products were examined using XRD and TEM techniques in order to characterize the morphological structure of their samples. The spatial distribution of temperature in the plasma was evaluated by in-situ emission spectroscopy. The self-absorption was taken into account by simulating an integrated radiation in relation to the Swan band d3 Πg −→ a 3 Πu(0,0), emitted by the C 2 radical.Also, the exhaust gases were characterized by gas chromatography during each test.

No abstract

No abstract

No abstract

This paper provides a simple manner to demonstrate the vortex effect, occurring inside a plasma reactor operating at atmospheric pressure, used for CH 4 and CO 2 reforming and their conversion to high added value products. The reactor has a specific design to preheat the incoming gas and, at the same time, to cool the reactor bulk. The trace printed on the conical electrode and in the reactor bottom represents a clearly manifestation of the vortex effect. The reactor is also provided with a postchamber to prevent environment reaction and get an expansion in plasma volume sustaining a stable discharge operation.